Importance of decreased intracellular phosphate and magnesium concentrations and reduced ATPase activities in spontaneously hypertensive rats.

A decrease in total magnesium content is not a direct proof of a decreased magnesium ion concentration. It could reflect a phosphate alteration or an ATP metabolism disorder. Plasma phosphate levels are lower in spontaneously hypertensive rats (SHRs) than in Wistar-Kyoto (WKY) rats, and defects in membrane regulation or mitochondrial ATP synthase occur. Only sparse data exist concerning cellular magnesium and phosphate concentrations in hypertensive cells. In aortic smooth muscle cells from 10 SHRs of the Münster strain and 10 age-matched normotensive WKY rats, the intracellular phosphate and magnesium content was measured by electron probe X-ray microanalysis (Camscan CS 24 apparatus, Cambridge, U.K.). The Mg++ content was 0.90+/-0.15 g/kg dry weight in SHRs versus 1.15+/-0.10 g/kg dry weight in WKY rats (p<0.05). Vascular smooth muscle phosphate content was 23.6+/-0.79 g/kg dry weight in WKY rats versus 15.81+/-1.22 g/kg dryweight in SHRs (p<0.01). In seven animals, erythrocytic ATP content was 180.2+/-102 in SHRs vs. 432+/-72 micromol/L cells in WKY rats (p< 0.01). The Na+/K+-ATPase activity was significantly decreased in hypertensive animals as compared to controls (6.49+/-2.3 vs. 12.64+/-2.9 nmol inorganic phosphate/mg protein/min (p< 0.01)). Aortic smooth muscle cells from SHRs are characterized by markedly lowered cellular phosphate and magnesium concentrations and an altered ATP metabolism, possibly due to a membrane defect or a magnesium deficit in hypertensive cells.     

RNA阵列技术检测自发性高血压大鼠肌浆网Ca2+-ATP酶和受磷蛋白基因表达

目的:探讨肌浆网Ca²⁺-ATP酶(SERCA)和受磷蛋白(PLB)在原发性高血压发病过程中的变化特点及其相互关系。方法:提取2、4、6、8、10、12不同周龄雄性自发性高血压大鼠(SHR)和正常血压大鼠(WKY)的心室肌、血管平滑肌、肝脏和肾脏组织的总RNA,共294个样品,利用高通量RNA阵列技术(RNAarray)检测SERCA和PLB基因在不同周龄SHR和WKY中mRNA表达谱改变。结果:SHR在6、8、10、12周龄血压出现显著高于同周龄WKY(均P<0.01),10、12周龄心室肌重量／体重比出现显著增加(均P<0.01),心肌和血管平滑肌SERCA的表达在4、6、8、10、12周龄出现显著高于同周龄WKY(P<0.05或P<0.01)。PLB基因表达在两组间无显著差异(P>0.05)。心肌的SERCA与PLB表达量比值在6、8、10、12周龄出现显著大于同周龄WKY(P<0.05或P<0.01),而血管平滑肌的SERCA与PLB表达量比值在4、6、8、10、12周龄出现显著大于同周龄WKY(P<0.05或P<0.01)。结论:肌浆网SERCAmRNA表达改变及SERCA与PLB比例失常是高血压发生和发展过程中重要的分子生物学机制。     

胰岛素对自发型高血压大鼠血管平滑肌细胞TGF β及其受体的调节作用

目的:从细胞增生、转化生长因子β₁和受体表达等方面,探讨胰岛素对自发型高血压大鼠血管平滑肌细胞(SHR VSMC)和正常血压Wista-Kyoto大鼠血管平滑肌细胞(WKY VSMC)的影响异同。方法:采用组织移植法培养SHR和WKY大鼠胸主动脉VSMC|用细胞计数仪和流式细胞仪分别检测细胞增生情况|TGF β及其受体的mRNA水平利用定量RT-PCR技术进行检测。结果:(1)胰岛素加强SHR VSMC的增生,而不影响WKY VSMC的增生。胰岛素加强SHR VSMC的增生,且呈剂量依赖方式(2)以20%小牛血清培养基培养VSMC, SHR VSMC的S期百分率为31.44%,而WKY VSMC的S期百分率仅为19.86%|以2%小牛血清培养基培养VSMC,SHR VSMC的G₀／G₁和S期百分率分别为73.23%和9.35%,加入胰岛素后,SHR VSMC的G₀／G₁降低为67.58%,S期百分率则增加到15.64%。但是,加入胰岛素前后,WKY VSMC各期百分率无明显变化|(3)RT-PCR分析结果表明,生长静止的SHR VSMC和WKY VSMC均有TGF β₁、Ⅰ型和Ⅱ型TGF β受体的表达,但SHR VSMC的TGFβ₁、Ⅰ型TGF β受体的表达量高于WKY VSMC的TGF β₁、Ⅰ型TGF β受体的表达量,胰岛素加强了WKY VSMC的TGF β₁、Ⅰ型TGF β受体的表达(P＜0.01和P＜0.05),而削弱了SHR VSMC相应分子的表达(P＜0.01和P＜0.05),胰岛素不影响二株系大鼠VSMC Ⅱ型TGF β受体的表达(P＜0.05)。结论:胰岛素对SHR VSMC和WKY VSMC的TGF β和它的受体表达具有不同的调节作用,这种异常调节作用可能和胰岛素加强SHR VSMC的增生密切相关。     

Early onset of a decreased intracellular magnesium and phosphate concentration in smooth muscle cell of SHR.

A decrease in total magnesium content is not a direct proof of a decreased magnesium ion concentration. It could reflect a phosphate alteration or an ATP metabolism disorder. Plasma phosphate levels are lower in spontaneously hypertensive rats (SHRs) than in Wistar-Kyoto rats (WKYs), and defects in membrane regulation or mitochondrial ATP synthase occur. Only sparse data exist concerning cellular magnesium and phosphate concentrations in hypertensive cells. In aortic smooth muscle cells from 10 SHRs of the Münster strain and 10 age-matched normotensive WKY rats, the intracellular phosphate and magnesium content was measured by electron probe X-ray microanalysis (Camscan CS 24 apparatus, Cambridge, U.K.). The Mg++ content was 0.09 +/- 0.15 g/kg dry weight in SHRs versus 1.15 +/- 0.10 g/kg dry weight in WKY rats (p < 0.01). Vascular smooth muscle phosphate content was 23.6 +/- 0.79 g/kg dry weight in WKY rats versus 15.81 +/- 1.22 g/kg dry weight in SHRs (p < 0.01). In aortic smooth muscle cells of one month old SHRs intracellular magnesium was measured as 1.05 +/- 0.08 versus 1.09 +/- 0.09 g/kg dry weight in WKYs. Intracellular phosphate concentration in one month old SHRs was 18.71 +/- 2.41 versus 21.36 +/- 1.25 g/kg dry weight in WKYs (eight animals in each group). Aortic smooth muscle cells of SHRs are caracterized by markedly lowered intracellular phosphate and magnesium concentrations, resulting in an altered ATP-metabolism, as described earlier. Possibly a membrane defect or a magnesium deficiency or disturbed magnesium channels are responsible for the early onset in the pathogenesis of primary hypertension.     

Temporal characteristics of cardiomyocyte hypertrophy in the spontaneously hypertensive rat.

BACKGROUND: The spontaneously hypertensive rat (SHR) is frequently used as model of cardiovascular disease, with considerable disparity in reported parameters of hypertrophy. The aim of this study was to assess the temporal changes occurring during the development and progression of cardiomyocyte hypertrophy in SHR, subsequent to pressure overload, compared to changes associated with normal aging using the normotensive Wistar-Kyoto (WKY) rat. METHODS: Ventricular cardiomyocytes were isolated from rats at 8, 12, 16, 20 and 24 weeks, and parameters of hypertrophy (cell dimensions, protein mass, de novo protein synthesis, and gene expression) and function (contraction and hypertrophic responsiveness in vitro) were assessed. RESULTS: Hypertension was evident at > or =7 weeks in SHRs. Heart:body mass ratio, cardiomyocyte protein mass and width were elevated (P<.05) in SHRs at 16-20 weeks compared to WKYs. In SHRs compared to WKYs at 16 weeks, there was a transient increase (P<.05) in protein synthesis, enhanced hypertrophic responsiveness to phorbol-12-myristate-13-acetate, and induced hypertrophic responsiveness to isoprenaline. Skeletal-alpha-actin mRNA was detected in SHR but not WKY cells at all ages. ANP mRNA was lower in SHR than in WKY cells at 8-20, but progressively increased (P<.05) from 12 to 24 weeks within SHRs. Contractile function increased (P<.05) at 20 weeks in SHR compared to WKY rats. CONCLUSION: Structural and functional changes occurring at the cellular level in the myocardium of SHR follow a distinct pattern, such that pressure overload was initially accompanied by expressional changes (8-12 weeks), followed by active hypertrophic growth and enhanced function (16-20 weeks), which subsequently decelerated as stable compensation was attained.     

不同年龄高血压大鼠血管平滑肌中ERK和MKP-1的表达

目的：研究不同年龄的自发性高血压大鼠（SHR）和Wistar Kyoto大鼠（WKY）主动脉平滑肌中丝裂原活化蛋白激酶（MAPK）及其磷酸酶（MKP-1）的表达及其与高血压的关系。 方法： 用tail-cuff测量大鼠尾动脉血压；分别用Western blotting法和RT-PCR法半定量测定血管平滑肌中磷酸化细胞外信号调节激酶（p-ERK）和MKP-1的蛋白表达以及MKP-1 mRNA的含量。 结果： （1）SHR的血压自8周龄起明显高于WKY（P<0.01），且随年龄增长而升高（P<0.05）至14周以后趋于稳定；（2）SHR主动脉平滑肌中的p-ERK表达明显高于同年龄的WKY（P<0.01），随年龄增长而递增（P<0.05），与血压呈正相关；（3）SHR主动脉平滑肌中MKP-1蛋白明显高于同龄WKY，而mRNA的表达在5周龄时明显高于WKY，之后均随年龄的增长而递减（P<0.05），与血压和ERK呈负相关，而WKY下降不明显。 结论： MKP-1在高血压的发生和发展过程中起重要作用，其表达逐渐下降可能是导致ERK激活增加，从而导致血管平滑肌细胞增殖、血压升高的重要原因。     

自发性高血压大鼠淋巴微循环功能受损

目的:观察自发性高血压大鼠(SHRs)淋巴微循环功能变化.方法:8周龄雄性SHR大鼠(SHR组)和WKY大鼠(WKY组),每组各10只.应用VasT rack测量两组大鼠微淋巴管自律运动;取胸导管分离原代淋巴管内皮细胞(LECs).应用免疫荧光和Western Blot检测LECs血管内皮生长因子受体3(VEGFR3)...     

自发性高血压大鼠FXYD5基因表达的时空分布

目的:研究大鼠FXYD5(FXYD domain-containing ion transport regulator 5)基因表达在自发性高血压大鼠（SHR）及正常血压大鼠（Wistar-Kyoto, WKY）的时间与空间分布差异。方法:取4周、8周、13周及21周龄SHR的肾脏、肝脏、肠系膜二、三级动脉分支、大脑和心脏组织，以同周龄WKY作对照，采用Northern blotting方法分析FXYD5mRNA表达丰度。结果:Northern blotting的结果显示：13周、21周龄SHR的肾脏组织FXYD5基因表达丰度较同周龄WKY低；在肺组织，除8周龄该基因的表达水平在SHR组略低于对照组外，其它周龄两组没有差别。结论:FXYD5基因在SHR中有着特异性的组织分布特点，并且在不同周龄的SHR， FXYD5基因在肾脏的表达水平不是恒定不变的，在时间上呈一钟形变化。提示FXYD5基因可能是一个高血压相关的基因，可能与高血压的发病有关。     

Role of smooth muscle cell membrane potential in neointima formation in arteries of spontaneously hypertensive rats

Based on observations that vascular smooth muscle cells (VSMC) from spontaneously hypertensive rats (SHR) have altered resting potentials as well as abnormal cell proliferation rates, neointima formation after controlled balloon injury was compared in arteries from SHR and Wistar Kyoto rats (WKY). SHR aortic VSMC showed hyperpolarized resting membrane potentials (−93±8 mV) when compared to those from WKY (−61±6 mV). Histomorphometric analysis of cross sections from aortic segments submitted to balloon injury showed reduced neointima formation in SHR (neointima/media ratio: 0.04±0.03) as compared to WKY (0.2±0.1). On the other hand, in injured carotid arteries, neointima formation was more extensive in SHR (neointima/media ratio 5.0±0.9) than in WKY (0.8±0.7), leading in most cases to luminal occlusion. Measurements of VSMC resting potential showed that carotid artery cells from SHR were depolarized with respect to those from WKY (−46±4 vs. −69±5 mV, respectively). The results demonstrate an inverse relationship between VSMC membrane polarization and neointima formation in SHR arteries, suggesting that genetic modifications in SHR determine a dysfunctional cellular physiology that may influence cell proliferation subsequent to injury.     

Role of Ca-dependent K channels in the membrane potential and contractility of uterus from spontaneously hypertensive rats

Membrane potentials and the contractile responses to prostaglandin F₂, oxytocin, bradykinin, 5-hydroxytryptamine and acetylcholine were determined in uteri from spontaneously hypertensive rats (SHR) and normotensive Wistar Kyoto rats (WKY), both in the absence and in the presence of the Ca²⁺-dependent K⁺ channel blocker apamin. Compared to WKY, the uterine smooth muscle from SHR was more reactive to all the agonists tested. In the presence of apamin, the contractile responses of WKY uteri were enhanced, whereas the responses of SHR uteri were either unaltered or decreased, so that the WKY responses became similar or even greater than those of SHR. Smooth muscle cell membrane potentials were lower in SHR than in WKY. Treatment with apamin did not affect the membrane potential of SHR cells, but caused depolarization of WKY cells. It is concluded that a reduced activity of Ca²⁺-dependent K⁺ channels in SHR uteri contributes to their lower membrane potentials and higher responsiveness to contractile stimuli by agonists, It is possible that uterine quiescence, essential for the normal fetal development, is impaired in SHR, resulting in lower uterine blood fluxes with consequent lower fetal and litter size and weight observed in this strain.     

阿托伐他汀对自发性高血压大鼠细胞色素P450羟化酶基因表达的影响

目的： 评价阿托伐他汀对自发性高血压大鼠（SHR）血压和细胞色素P450羟化酶(CYP)4A1的调节作用。方法： 18只SHR随机分为3组：SHR对照组、阿托伐他汀50 mg组(HATV组)和10 mg组(LATV组)；6只Wistar-Kyoto大鼠(WKY)作为正常对照组。给药共10周,分别于给药前和给药后每2周测量大鼠尾动脉收缩压(SBP)；RT-PCR、Western blotting法检测心、肝、肾及主动脉中CYP4A1 mRNA和蛋白质表达；并测定血脂含量。结果： 用药前SHR各组SBP均显著高于WKY组(P<0.01)；HATV组在给药后第6、8、10周和LATV组在给药后第10周SBP明显低于SHR对照组(P<0.05或P<0.01)。在CYP4A1 mRNA及其蛋白质表达中，SHR对照组4种组织均明显高于WKY组(P<0.01或P<0.05)；给药10周后，HATV组心、肾及主动脉和LATV组肾和主动脉的表达均明显低于SHR对照组(P<0.01或P<0.05)；同时，用药2组血脂水平亦明显低于SHR对照组(P<0.01或 P<0.05)。结论： 阿托伐他汀可下调CYP4A1基因的表达，这可能是其降低血压的作用机制之一。     

螺内酯和缬沙坦对高血压大鼠心肌细胞外信号调节激酶的影响

目的:观察血管紧张素Ⅱ受体拮抗剂缬沙坦和醛固酮受体拮抗剂螺内酯对SHR心肌中活化的ERK的影响。方法:将18只雄性SHR随机分为三组,每组6只。其中两组分别用缬沙坦30mg/kg/天、螺内酯20mg/kg/天溶于饮水灌胃,连续治疗13周;对照组给正常饮水,并与Wist-ar-kyoto大鼠(WKY)比较。用Western-blot方法检测大鼠心肌磷酸化ERK的表达。结果:SHR对照组心肌磷酸化ERK/actin值高于其余三组(P<0.01),螺内酯和缬沙坦组高于WKY组(P<0.01),两用药组之间无差异。结论:血管紧张素Ⅱ受体拮抗剂缬沙坦和醛固酮受体拮抗剂均能通过抑制ERK途径而抑制左室肥厚和心肌纤维化。     

自发性高血压大鼠一侧颈动脉去外膜后结构和功能的变化

目的： 研究自发性高血压大鼠（SHR）去除一侧颈动脉外膜后血管结构和功能的变化。方法: 8只13周龄雄性SHR作为SHR对照组，8只同周龄雄性WKY大鼠作为正常血压对照组（WKY组）。机械和化学方法去除大鼠右侧颈动脉外膜，左侧作假手术对照。4周后，电磁流量计测量双侧颈动脉血流量，放免法测定血浆及双侧颈动脉血管紧张素Ⅱ（Ang Ⅱ）浓度。取双侧颈动脉制成光镜标本，病理图像分析系统测定颈动脉管腔横截面积（LA）、内弹力层围绕面积（IELA）、外弹力层围绕面积（EELA），评价内膜和中膜增生程度。RT－PCR法检测颈动脉血管紧张素转换酶2 mRNA（ACE2 mRNA）表达，免疫组化法检测ACE2 mRNA、蛋白激酶C-ζ（PKC-ζ）和胞外信号调节激酶1/2（ERK1/2）蛋白表达。结果: （1）SHR对照组双侧血管内膜比WKY组明显增生(P<0.01)，中膜面积显著大于WKY组（P<0.05, P<0.01）；去外膜侧内膜增生较外膜完整侧显著（P<0.05）；（2）SHR对照组去外膜侧血流速度明显少于WKY组和SHR对照组外膜完整侧（均P<0.01）；（3）SHR对照组血浆及双侧颈动脉AngⅡ浓度均明显高于WKY组 (P<0.01)，去外膜侧颈动脉AngⅡ浓度明显高于外膜完整侧（P<0.01）；（4）SHR对照组双侧血管ACE2 mRNA表达均显著少于WKY组（P<0.01），去外膜侧ACE2 mRNA表达显著少于外膜完整侧（P<0.01）；（5）SHR对照组PKC-ζ和ERK1/2在双侧血管的表达均显著高于WKY组（P<0.01），去外膜侧PKC-ζ和ERK1/2表达显著高于外膜完整侧（P<0.01）。结论: SHR去除一侧颈动脉外膜后血管内膜增生明显，中膜面积增大，血流速度减慢；这一变化可能与ACE2 mRNA表达减少、PKC-ζ和ERK1/2蛋白表达增加有关。     

螺内酯和缬沙坦对高血压大鼠肠系膜微动脉重塑的影响

目的:观察盐皮质激素受体拮抗剂螺内酯和血管紧张素Ⅱ(AngⅡ)AT1受体拮抗剂缬沙坦对自发性高血压大鼠(SHR)肠系膜微动脉形态、超微结构和Ⅰ型胶原mRNA表达的影响。方法:将18只雄性SHR随机分为三组,每组6只,其中两组分别用螺内酯20mg/kg/天、缬沙坦30mg/kg/天溶于饮水中灌胃,连续治疗13周,对照组不用药,正常饮水,并与WKY大鼠(6只)比较。鼠尾法测量大鼠动脉收缩压;应用计算机图像分析系统,计算大鼠肠系膜微动脉管壁与管腔横截面积比;用透射电镜观察大鼠肠系膜微动脉结构的变化;用RT-PCR方法检测肠系膜微动脉Ⅰ型胶原mRNA水平。结果:实验第13周末,SHR对照组血压明显高于WKY组(P<0.01);缬沙坦组和螺内酯组血压明显低于SHR对照组(P<0.01);缬沙坦组的血压与WKY组接近(P>0.05)。螺内酯组和缬沙坦组大鼠肠系膜微动脉的中膜厚度/管腔半径值及中膜面积/管腔面积值仍显著大于WKY组(P<0.05),但较SHR组明显降低(P<0.01)。透射电镜见SHR肠系膜动脉壁有大片纤维组织增生,螺内酯组和缬沙坦组肠系膜动脉壁内仅见少许纤维组织增生。螺内酯组和缬沙坦组Ⅰ型胶原mRNA水平明显低于SHR对照组(P<0.01)。结论:螺内酯和缬沙坦均能抑制SHR的Ⅰ型胶原合成,表明盐皮质激素受体和AngⅡ受体在高血压阻力血管的重塑中起着重要作用。     

胰岛素对高血压大鼠血管平滑肌细胞血小板源生长因子A链和转化生长因子β1表达的影响

探讨胰岛素对体外培养的血管平滑肌细胞（VSMC）增生及其长型血小板源生长因子A（PDGF－A）链和转化生长因子β1（TGFβ1）mRNA表达的影响。结果发现：（1）胰岛素促进自发型高血压大鼠的血管平滑肌细胞（SHR－VSMC）增生,且呈浓度依赖性;而对正常血压的Wistar-kyota大鼠的血管平滑肌细胞（WKY－VSMC）增生无影响。（2）定量RT－PCR分析显示,胰岛素加强WKY－VSMC的TGFβ1mRNA的表达（P＜0．01）。但是减少SHR－VSMC的TGFβ1mRNA的表达（P＜0．001）。（3）胰岛素对二株系VSMC的长型PDGF－A上对表达水平无影响。结果表明,胰岛素选择性地加强SHR－VSMC的增殖,而对WKY－VSMC的增殖无影响。这可能和胰岛素能上调WKY－VSMC自分泌TGFβ1有关;而在SHR－VSMC,此反馈抑制失常,结果SHR－VSMC加速生长。     

高血压大鼠红细胞膜钙泵功能障碍机理的初步分析

本工作比较自发性高血压大鼠(SHR)和肾性高血压大鼠(RHR)及对照大鼠红细胞膜Ca~(2+),Mg~(2+)-ATP酶(钙泵)活性及其对CaM、TFP、川芎嗪和硝苯吡啶(Nifedipine、Nif)等的反应,目的是分析高血压时钙泵功能障碍的机理,并寻找能有效提高钙泵活性的药物,为高血压防治提供有效措施。 结果表明SHR及RHR基础钙泵活性明显低于相应对照大鼠钙泵活性;原因之一可能与高血压动物质膜钙泵对钙泵抑制剂TFP的敏感性增加有关,对RHR,川芎嗪作用很类似TFP。提示此药有CaM拮抗作用。Nif除了公认为钙通道阻断剂外,本实验表明对RHR它还有激活钙泵的作用。     

靶向S1P2基因的siRNA有效片段慢病毒载体的筛选

目的:筛选能显著抑制原代培养的自发性高血压大鼠(spontaneously hypertensive rats,SHR)阴茎海绵体平滑肌细胞内1-磷酸鞘氨醇受体2(sphingosine-1-phosphate receptor 2,S1P2)基因表达的siRNA慢病毒载体。方法:SHR及SD大鼠各5只用于原代培养阴茎海绵体平滑肌细胞并分成6组,每组5个样本,每个样本约1.0×105个细胞,分别为携带靶向S1P2基因的siRNA-1~3号靶点的SHR慢病毒转染组(SHR siRNA-1、SHR siRNA-2和SHR siRNA-3组)、携带慢病毒空载体的SHR转染组(SHR GFP组)、SHR未转染对照组(SHR control组)和SD大鼠对照组(SD control组)。将靶向S1P2的siRNA片段的慢病毒载体,以感染复数(MOI)=60转染各组SHR阴茎海绵体平滑肌细胞,于转染72 h后荧光显微镜下观察细胞荧光表达情况,用Western blot分析各组S1P2、ROCK1、ROCK2和eNOS在阴茎海绵体平滑肌细胞内的表达变化,RT-PCR检测各组阴茎海绵体平滑肌细胞S1P2、ROCK1和ROCK2的mRNA的表达。结果:荧光显微镜下观察SHR siRNA-1、SHR siRNA-2、SHR siRNA-3和SHR GFP组细胞转染效率均80%;SHR GFP组与SHR control组相比,S1P2、ROCK1和ROCK2的mRNA和蛋白表达无明显差异,SHR siRNA-1、SHR siRNA-2、SHR siRNA-3和SD control组均显著低于SHR control组(P0.05)。而SHR siRNA-1、SHR siRNA-2、SHR siRNA-3和SHR GFP组eNOS蛋白表达与SHR control组相比均无显著差别,但SD control组显著高于SHR control组(P0.05)。结论:3组针对S1P2的siRNA慢病毒载体均能显著抑制SHR阴茎海绵体平滑肌细胞内S1P2的表达,下调ROCK1和ROCK2表达,其中靶向S1P2的siRNA-1抑制效率最高。     

Cytochemical investigation of p-NPPase activity in rat cardiac muscle.

The cytochemical demonstration of the atrial cardiac myocyte pumping activity has been made by detecting p-nitrophenylphosphatase (NPPase), which is used by investigating of Na(+)-K(+)-ATPase and H(+)-K(+)-ATPase activities. The fine ultrastructural localization of these enzymes was studied using cytochemical methods with cerium as a capturing agent. Na(+)-K(+)-ATPase was localized on the atrial muscle cell plasma membrane, T-tubule membrane, endothelial cell nuclear membrane, and cardiac myocyte nuclear membrane. H(+)-K(+)-ATPase was localized on the atrial muscle cells plasma membrane, T-tubule membrane, and sarcoplasmatic reticulum. The present findings indicate that the transporting metabolic activity of the heart as an endocrine organ is realized by the interaction between p-NPPases.     

Increased osteocyte apoptosis during the development of femoral head osteonecrosis in spontaneously hypertensive rats

We investigated the presence of osteocyte apoptosis in the necrotic trabeculae of the femoral head of spontaneously hypertensive rat (SHR) using the in situ nick end labeling (TUNEL) method and transmission electron microscopy. The occurrence of osteonecrosis and ossification disturbance was significantly higher in SHR compared with Wistar Kyoto (WKY) rats, and Wistar (WT) rats used as control animals (P < 0.01). A high population of TUNEL positive osteocytes was detected mainly in 10- and 15-week-old SHRs. Sectioned examination of the femoral head of SHRs and WKY rats by electron microscopy revealed apoptotic cell appearances such as aggregation of chromatin particles and lipid formation. In contrast, a positive reaction was significantly lower in osteocytes in the femoral heads of WT rats (P < 0.01). Our results indicate that apoptosis forms an important component of the global pathologic process affecting the femoral head of SHR, which leads to osteonecrosis in this region.     

阿托伐他汀影响自发性高血压大鼠血压的机制探讨

目的：探讨阿托伐他汀控制自发性高血压大鼠（SHR）高血压的机制，研究阿托伐他汀对SHR血浆内皮素-1（ET-1）和主动脉一氧化氮合酶（NOS）的影响，以及对SHR的主动脉平滑肌细胞（ASMC）凋亡和P27蛋白表达的影响。 方法： 选用8周龄SHR 12只，随机分为阿托伐他汀治疗组（ATV组, n=6）和SHR组（n=6），并以同周龄WKY（n=6）作为对照。ATV组给以阿托伐他汀（50 mg·kg-1·d-1）灌胃。10周后观察3组大鼠血压、血清总胆固醇（TC）、总甘油三酯（TG）含量变化，血浆ET-1和主动脉NOS活性的改变，以及TUNEL法检测ASMC凋亡率，测定动脉ASMC P27蛋白表达。 结果： 阿托伐他汀给药10周后，ATV组动脉收缩压显著低于SHR组［（134.17±3.60）mmHg vs （173.33±3.78）mmHg, P<0.01］；ATV组血清TC和TG浓度均显著低于SHR组（P<0.01, P<0.01）。同时，阿托伐他汀显著降低SHR血浆ET-1水平［（130.04±40.07）ng/L vs （196.74±59.69）ng/L，P<0.05］和增加SHR主动脉NOS活性［(0.189±0.040）kU/g protein vs （0.124±0.057）kU/g protein，P<0.01］；ATV组ASMC凋亡率显著高于SHR组（16.94%±3.08% vs 9.01%±2.36%, P<0.01）；ATV组ASMC P27蛋白表达阳性率显著高于WKY大鼠（33.02%±5.01% vs 24.25%±4.41%, P<0.05），而SHR组该指标明显低于WKY大鼠（16.08%±7.09% vs 24.25%±4.41%, P<0.05）。 结论： 阿托伐他汀控制SHR血压增高，其机制可能与降低SHR的血浆ET-1水平和增高主动脉NOS活性，以及增高ASMC凋亡率和P27蛋白表达阳性率有关。